Effects of alkaline-earth metals on the structure, adsorption and catalytic behavior of iron-based Fischer–Tropsch synthesis catalysts

Effects of impregnation strategy on structure and performance of bimetallic CoFe/AC catalysts for higher alcohols synthesis from syngas

“…Fe is another popular catalytic metal for the F-T synthesis, which possesses different hydrogenation activities from Co element [28,29]. So far, CoFe bimetallic catalysts have been extensively investigated for F-T synthesis [30][31][32][33][34][35][36][37][38][39][40], yet few reports have indicated that these bimetallic catalysts could produce mixed alcohols [30][31][32].…”

Chapter 3. Catalytic conversion of biomass-derived synthesis gas to fuels

“…Alkaline-earth metals (Mg, Ca, Sr, Ba) have properties similar to those of alkali metals, but they have higher melting points. 201,203 It has been reported that they increase the total liquid product rate and, at the same time, lower the gas product fraction. 203 They facilitate carburization, CO chemisorption and suppress H 2 adsorption.…”

“…204 Alkaline-earth metal promotion also strengthens Fe-O bonds in the fresh catalysts, which inhibits the removal of oxygen from iron oxide phases in presence of H 2 . 201 Although the activity in FT synthesis is similar for both promoted and unpromoted catalysts, 202 alkaline-earth metals lead to a reduction in methane formation. 200 In particular, Sr has a strong influence on the inhibition of light hydrocarbon production.…”

“…[199][200][201] On the other hand, alkalis usually lead to carbon deposits on the catalysts surface during the reaction. 201 Moreover, these metals have low melting points and, therefore, they can easily move over the catalyst surface. Both effects result in a decrease of the stability of iron-based catalysts under FT synthesis conditions.…”

“…Both effects result in a decrease of the stability of iron-based catalysts under FT synthesis conditions. 201,202 2.3.2.1.2 Alkaline-earth metals. Alkaline-earth metals (Mg, Ca, Sr, Ba) have properties similar to those of alkali metals, but they have higher melting points.…”